ATTENUATION OF CHEMOTHERAPY INDUCED MYELOSUPPRESSION

描述：（申请人摘要）旨在改善 逆转录病毒转导化疗的骨髓抑制副作用 已经建立了化学保护基因的治疗固体 肿瘤的 胸苷酸合成酶（TS）是一种很好的候选药物 耐药基因治疗，因为1）它在DNA中起着关键作用 通过提供胸苷酸的唯一从头来源来进行生物合成，2）几种 最近已经开发了新的TS抑制剂，并在临床上用于治疗。 试验，和3）许多TS-定向抑制剂的剂量限制性毒性， 骨髓抑制 这些抑制剂包括ZD 1694、LY 21514、 ZD 9331、1843489和AG 337。 除了减轻副作用外， 化疗时，赋予耐药性的基因也可以用作显性基因。 选择标记 申请人最近表明， 使用二氢叶酸还原酶作为体内 选择遗传修饰的造血细胞。 这个目标 应用是建立使用基因转移的可能性， 胸苷酸合成酶，以减轻靶向TS的毒副作用 抑制剂，并确定TS是否可以用作显性选择标记。 本申请的具体目的可以概括为：1）确定 TS的突变导致对核苷酸的亲和力降低， 抗叶酸抑制剂，2）构建编码变体的逆转录病毒载体 TS和先前表征的DHFR变体。 3)测试是否存在电阻 TS和DHFR抑制剂可防止化疗诱导的 骨髓抑制和如果造血干细胞的体内选择可以 在移植的小鼠中实现。 4)确定重组逆转录病毒 其编码TS和DHFR的变体赋予转导的 人骨髓细胞、人脐带血细胞和人 单核外周血细胞

DESCRIPTION: (Applicant's Abstract) Clinical trials aimed at ameliorating the myelosuppressive side effects of chemotherapy by retroviral transduction of chemoprotecting gene have been established for the treatment of solid tumors. Thymidylate synthase (TS) is an excellent candidate for drug resistance gene therapy because 1) it plays a critical role in DNA biosynthesis by providing the only de novo source of thymidylate, 2) several novel inhibitors of TS have recently been developed and are in clinical trials, and 3) the dose limiting toxicity of many TS-directed inhibitors is myelosuppression. Included among these inhibitors are ZD1694, LY21514, ZD9331, 1843489 and AG337. In addition to attenuating side effects of chemotherapy, genes that confer drug resistance can also be used as dominant selectable markers. The applicant has recently shown the feasibility of using dihydrofolate reductase as a chemoprotecting agent for in vivo selection of genetically modified hematopoietic cells. The goal of this application is to establish the possibility of using gene transfer of thymidylate synthase to attenuate the toxic side effects of TS targeted inhibitors and determine if TS can be used as a dominant selectable marker. The specific aims of this application can be summarized as: 1) Determine mutations of TS that result in decreased affinity for nucleotide and antifolate inhibitors, 2) Construct retroviral vectors that encode variants of TS and a previously characterized variant of DHFR. 3) Test if resistance to TS and DHFR inhibitors protect against chemotherapy induced myelosuppression and if in vivo selection of hematopoietic stem cells can be achieved in transplanted mice. 4) Determine if recombinant retroviruses that encode variants of TS and DHFR confer chemoprotection to transduced human bone marrow cells, human umbilical cord blood cells, and human mononuclear peripheral blood cells.